User-Contributed Guide

Introduction

The Creality Ender 3 has become a very popular low cost printer option. It's not without its downsides, however. Loud motors, drivers, and fans can be maddening, and the lack of a dynamic web interface and network connection makes interacting with it more painful than it needs to be. This is not to mention the lack of thermal runaway protection in the Creality build of Marlin.

However, the small build volume, smaller motors, and single extruder design is a perfect fit for the recently released Duet Maestro electronics board, which brings the power and flexibility of RepRapFirmware into a smaller, lower cost package, while still maintaining powerful and quiet Trinamic drivers.

The combination of low cost but well built printer frame and suitable mechanics with the power and flexibility of the Duet Maestro and RepRapFirmware work together to create a very affordable and capable machine.

This series of guides will go through the process of upgrading a stock Ender 3 Pro with a Duet Maestro, from wiring, to firmware configuration, and basic tuning steps. Later guides will go into more advanced feature upgrades like installing alternate fans, LED lighting, and Z probes like the BLTouch.

Even though these guides will show an Ender 3, the procedures shown can be applied to other Cartesian printers.

Parts

Video Overview

Once you have your Ender 3 pro up and running, you’ll want to plan out your upgrade path before taking it apart. At the very least you’ll need an adapter to mount the Duet Maestro board in the Ender 3 electronics enclosure.

You also have the option of replacing the enclosure entirely with something of your choosing. There are a few printable enclosure options on Thingiverse. Though if you go this route, you may need to extend some of the wiring.

Next, go through the LCD menu and record certain details about the firmware settings, mainly axis length, steps per mm, acceleration, max speed, and jerk settings. This will be required when we use the RepRapFirmware Web Configurator to prepare our starting configuration files.

Most of this information can also be found in the Marlin Configuration.h file. Your SD card from Creality may contain the Marlin files, and it can be downloaded from the Creality website or GitHub repository.

First, we need to take the old Creality board out. Disconnect and remove the display from the frame. Then disconnect the Z end stop wire from the end stop. This will make the next steps easier. Now remove the screws holding the electronics enclosure together. Two on the front, two on top, and 3 underneath.

Once the electronics enclosure is loose, you can take the base off and expose the board. Remove the 4 screws holding down the board to the plate. Set all the screws aside where you won’t lose them.

Creality has secured the plugs with a blob of hot glue as strain relief, which is nice, but kind of a pain in our case. Carefully use a small flat blade screw driver to pry the glue blob off the connector. In my case the glue wasn’t very strong and the connector came loose with a little prying.

Before unplugging the connectors, make sure they are properly labeled and maybe take a picture to help identify where everything goes again for reassembly or if you ever wanted to revert back to the stock setup.

Because the front plate of the enclosure doesn’t have the necessary cutouts for the Maestro, we’ll have to make some alterations. First test fit the Maestro board and mark the inside of the front plate for where you need to cut.

You’ll need access to the Ethernet port, the SD card slot, the micro USB connector, and the reset button. You may also want to have some holes to see the status LEDs.

I’ll leave it up to you how you modify the plate. In my case I used a drill and a rotary tool with a reinforced cutting wheel to make a rough cut, and then used a file to clean up the edges.

Attach the adapter mount to the plate using the 4 original screws. Then attach the Maestro to the mount using 4 6mm M3 screws. Use the clear plastic washers that came with the Maestro in the bag of connectors.

Next, we will re-terminate the wires using the provided crimp connectors. How you connect the wires to the board is up to you, but in this case, we will be snipping off the existing connector, stripping the ends, and re-crimping a new connector that fits the Maestro specifically.

The only exception is the motor plugs, which we will modify slightly so they can plug into the Maestro as is. Pay close attention to the orientation of the Creality plugs and the markings on the Creality board in order to preserve polarity of the connectors.

Take out and sort the connector ends that came with the Maestro. You’ll need a crimping tool.

The Duet 2 Maestro has three controlled fan connectors FAN0, FAN1 and FAN2 plus one always-on fan connector. Make note of which fan is which from the Ender 3 board.

The fan voltage is jumper-selectable in 2 blocks. Ensure that the jumpers next to the fan connectors are set to the correct position. These jumpers select the voltage that will go to the fan pins. In our case, the Ender 3 uses 24v and the stock fans are also 24v, so we will leave the jumper bridging the VFAN pin with VIN.

In my case, the part cooling fan has the yellow (+) and blue (-) wires, and the hot end heatsink fan has unterminated bare red (+) and black (-) wires, and the case fan has a terminated red (+) and black (-) wires.

The part cooling fan will plug into Fan0, the hot end fan into Fan1, and the case fan into Fan2.

The always on fan connector can be used for another fan, or even LED lighting.

The hot end heater should ideally use the included bootlace ferrules. (White plastic with round tube) but due to the tight quarters of the Ender 3 Pro case, we will use the bare wires directly in the screw down terminal block.

Ensure that the wires are twisted tightly together, insert the wire end completely into the E0 heater terminal, and screw it down firmly.

You may need to trim the length of the bare wire so that it fits entirely within the connector with no visible wire strands.

If you do wish to use the ferrules with the stock enclosure, you will likely need to make a small cutout for clearance, or use a different enclosure all together.

The stepper motor connectors technically do not need to be re-crimped, however the ridges on the motor plugs that ensure they can only be plugged in one way to the Creality board need to be clipped off. A pair of side cutters works well.

This has the advantage of saving a lot of time crimping as well as keeping all the wires in the correct order. However, it does have the disadvantage of no longer being keyed, so you must ensure they are plugged into the board the right way around.

The side of the plug that you snipped the guides off will go towards the white pillar of the board connector. It may help to mark this side of the motor plug with a dot to help you keep track.

If the motor connections are plugged in the wrong way round, no damage to the electronics will occur, but the motors will run backwards. You'll either need to flip the plug or change the motor direction in software.

Further information on connecting motors can be found here on the wiki.

The end stop connectors will need to be redone. The Creality end stop switches have only two wires for signal and ground, but the Maestro end stop connectors have 3 wires: signal, ground and 3.3v power.

We will use the 3 wide connector and place the wires in the outer two spots, leaving the center unpopulated. The order of the two wires does not matter, so long as they are connected to the outside pins only.

Further information on connecting end stops can be found here on the wiki.

Lastly, we will need to connect the 12864 LCD board using the included ribbon cable as well as our additional ribbon cable. We will be using the EXP1 and EXP2 pin blocks on the Maestro board to connect to EXP1 and EXP2 connector ports on the back of the Ender 3 12864 display PCB.

If you are using two 10-way ribbon cables you will have to reverse the plastic shell of EXP1 and EXP2 on the LCD by pulling them off gently but firmly with a pair of pliers, rotating 180 degrees and then reinserting them on the pins. This will keep the pins aligned properly as the ribbon cable connectors are keyed.

Alternatively, you can use the ribbon cable that came with the Ender 3 for EXP2 and use jumper wires with Dupont connectors to connect directly to the needed pins. See this forum thread for more information on this method. https://forum.duet3d.com/topic/7609/conf...

Once you’ve got everything wired up you can reinstall the case onto the frame.

You may find it easier to disconnect some wires temporarily and reconnect them once it’s installed. It’s a tight fit, but it will all fit. I suggest leaving the 2 screws on the front loose and align and tighten the screw directly under the bed first.

Note that the VIN power, Bed wires, and hot end wires stick out from the edges of the board and will press up against the side of the case slightly. For the VIN and bed wires you will need to bend the spade connector upwards to fit back onto the frame.

Once you’ve got all your wires reconnected, you can use some zip ties, etc., to provide some strain relief for the bundle leaving the case.

Now reinstall the bottom plate with the case fan attached. It will take a little bit of wiggling to get the tab past the edge of the board. Once all the small screws are secured, you can finally tighten to two large screws on the front.

The case fan is installed in the same orientation as it was originally which pulls air out of the case, which should be ideal as it will draw in fresh air through the grills right next to the driver chips. For the currents and loads being used on the stock Ender 3 Pro this should be adequate cooling.